The standard contract is 5 BTC; the micro contract is 0.1 BTC, which at a $60,000 price is $6,000 of notional and the practical size for most accounts. Settlement is in cash against the bitcoin-reference-rate, so no coins, wallets or exchanges are involved.
These contracts differ from the perpetual-futures that dominate offshore crypto venues in three ways that matter: they expire monthly, they have no funding-rate, and they clear through a regulated clearing-house with span-margin rather than an exchange's own liquidation engine.
The CME basis — futures above spot — is widely quoted as a sentiment gauge and is the leg institutions harvest in a cash-and-carry-arbitrage against spot bitcoin ETFs.
Example: bitcoin spot $60,000, the three-month future $61,800. That is a 3% basis, about 12% annualised, available to anyone who can hold spot and short the future.
Related: bitcoin-reference-rate, ether-futures, perpetual-futures, cash-and-carry-arbitrage, funding-rate